Immortal and mortal clonal lymphocyte lines from channel catfish:: comparison of telomere length, telomerase activity, tumor suppressor and heat shock protein expression
Immortal and mortal clonal lymphocyte lines from channel catfish:: comparison of telomere length, telomerase activity, tumor suppressor and heat shock protein expression
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DOI：
10.1016/s0145-305x(01)00049-0
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发表时间：
2002-01-01
影响因子：
2.9
通讯作者：
Bengtén, E
中科院分区：
文献类型：
--
作者：
Barker, K;Khayat, M;Bengtén, E
对斑点叉尾鱼自主（永生）和非自主（死亡）白细胞系的端粒长度和端粒酶、Hsp70和p53的表达（细胞永生化中潜在的重要因素）进行了表型分析。自主细胞组成型表达端粒酶，而非自主细胞表达这种活性只是短暂的。这一观察结果，再加上低端粒酶活性水平，在新鲜分离的白细胞，表明端粒酶在鲶鱼白细胞的表达是激活诱导。相反，这两种类型的细胞系表现出非常相似的模式显着缩短端粒，这表明端粒酶不稳定鲶鱼端粒，直到达到一个关键的短长度。北方分析表明，像端粒酶，热休克蛋白70基因的表达是组成性的自主细胞和瞬时的非自主细胞。与此相反，p53 mRNA水平出现类似的低和noncycling在两个长期培养类型的鲶鱼细胞，无论文化的情况。此外，通过Western分析注意到，两种类型的细胞都显示出多种大小形式的p53蛋白。后者的观察意味着，截短的p53蛋白可能不直接参与在体外永生化过程中的癍点叉尾？鱼白细胞。(C)2001爱思唯尔科技有限公司版权所有。
Channel catfish autonomous (immortal) and nonautonomous (mortal) leukocyte lines were phenotyped with respect to telomere length and the expression of telomerase, Hsp70 and p53, potentially important factors in cellular immortalization. The autonomous cells constitutively expressed telomerase whereas the nonautonomous cells expressed this activity only transiently. This observation, coupled with the low telomerase activity level seen in freshly isolated leukocytes, suggests that telomerase expression in catfish leukocytes is activation induced. In contrast both types of cell lines exhibited quite similar patterns of significantly shortened telomeres, suggesting that telomerase does not stabilize catfish telomeres until a critical short length is reached. Northern analyses indicated that, like telomerase, Hsp70 gene expression was constitutive in autonomous cells and transient in nonautonomous cells. In contrast, p53 mRNA levels appeared similarly low and noncycling in both longterm cultured types of catfish cells, regardless of the culture situation. Furthermore it was noted, by Western analyses, that both types of cells display multiple sized forms of p53 proteins. This latter observation implies that truncation of p53 protein is probably not directly involved in the in vitro immortalization process of channel catfish leukocytes. (C) 2001 Elsevier Science Ltd. All rights reserved.